Burner control for tending fire



March 14, 1944. L. R. TEEPLE 2,344,183

BURNER CONTROL FOR TENDING FIRE Filed Feb. 8, 1941 4 Sheets-Sheet 1 OFFON lNL/ENT'UR 46 -L,.R'.TEEFL QM I" IH/ MOTOR HT' cnourm MOTOR 0 /5,. 1.bTrURA/EY March 14, 1944. l... R. TEEPLE 2,344,183

BURNER CONTROL FOR TENDING FIRE Filed Feb. '8, 1941 4 Sheets- Sheet 2DTrUR/VEY March 14, 1944. R. TEEPLE 2,344,183

BURNER CONTROL FOR TENDING FIRE Filed Feb. 8, 1941 4 Sheets-Sheet 3lNL/EN TUR L. R. TEEF'L E.

LITTER/V5) March 14, 1944. TEEPLE 2,344,183

BURNER CONTROL FOR TENDING FIRE Filed Feb. 8, 1.941 4 Sheets-Sheet 4 [Nl/z/vrofi L TEE/=25 v 5 Patented Mar. 14, 1944 UNITED STATES PATENTOFFICE BURNER CONTROL FOR TENDING FIRE Lawrence R. Teeple, Portland,Oreg.

Application February 8, 1941, Serial No. 378,093

3 Claims.

This invention relates generally to Stoker controls and particularly toa clean fire Switch.

The main object of this invention is to devise a method forautomatically controlling a stoker during the period immediatelyfollowing any manual shut-down of the 'stoker for fire tending purposes.

The second object is to construct; an apparatus whereby a stoker isprovided with a manual cutout switch for fire tending purposes, andwherein there is provided an automatic means for closing the manuallyoperated switch after a given lapse of time following the manual openingof said switch.

The third object is to provide a method of insuring the automaticresumption of service after a delay period following manual shut-down ofa stoker for the purpose of tending the fire.

The fourth object is to provide a stoker timer adapted automatically toreturn the stoker to nor-'- mal operation following a shut-down periodinitiated manually for the purpose of removing clinkers or otherwisetending to the stoker.

The fifth object is to provide a shut-down switch in the normal controlcircuit for a stoker and an actuator for the switch which, when manuallymoved to off position, will automatically return to on"'positionfollowing a predetermined delay period.

The sixth object is to provide a manually initiated automaticallyterminated shut-down period for tending a. stoker employing timingmechanism commonly associated with normal control of such a stoker.

These and other objects are accomplished in the manner set forth in thefollowing specification as illustrated in the accompanying drawings, inwhich Fig. 1 is a side elevation of a complete operating control unit.

Fig. 2 is a plan of Fig. 1. r

Fig. 3 is a diagrammatic view of the control circuit showing the mannerin which the device is connected.

Fig. 4 is a side elevation of one gear from the time train of theoperating control having the operating mechanism connected to the gear.This view is taken along the line 4-4 in Fig. 2.

Fig. 5 is a front elevation of Fig. 4, showing the pawl in aninoperative position. I

Fig. 6 is a view similar to Fig. 5, but showing the pawl in an operativeposition.

Fig. 7 is a diagrammatic view of an alternative form of the deviceshowing the clean fire switch closed.

iii

Fig. 8 is a partial end elevation of Fig. 7.

Fig. 9 is a view similar to Fig. 7, but showing the clean fire switchopen.

Fig. 10 is a partial end elevation of Fig. 9.

Fig. 11 is a bottom view of Fig. 9.

Fig. 12 is a diagrammatic view of a modified form of the deviceembodying a thermally actuated means for operating the clean fire switchwhich is shown in an open circuit position, in which the stoker motorcannot be operated.

Fig. 13 is a view similar to Fig. 12, but showing the parts in a closedcircuit position in which the stoker motor can be operated.

Fig. 14 is a front elevation of the first element A in the operatingcam.

Fig. 15 is a front elevation of the second element in the operating cam.

Fig. 16 is a front elevation of the third section of the operating cam.

Similar numerals refer to similar parts throughout the several views.

Referring in detail to the drawings there are shown in Figs. 1 and 2assembled views of the complete unit for which the front plate l5 formsa base. Through the plate l5 or l5-A extends the shaft l6 which revolvescontinuously at the rate of one half revolution per hour on whose outerend is mounted the adjustable cam H, the function of which is to operatethe motor controlling switch l8 at predetermined intervals of time. Forexample, if it is desired to operate the stoker one seven minute periodduring each hour, in the event there are no calls for heat from othersources, the indicators l9 and 20 are set as shown in Fig. 1; then asthe cam l1 revolves on its shaft 16, the stoker motor will be operatedfor seven minutes out of an hour and shut down for 53 minutes as aminimum of operation. The hold fire cam l1 consists of a plurality ofsuitably notched concentric laminations adjustably disposed about acommon hub, and held in position by a screw which passes throughregistering holes in the onehalf hour, hour, or two hour positions. Thisarrangement merely serves to provide an adjustment for the length of thecam lobes.

The hold-fire cam I1 is provided with an arcuate window 99 through whichthe settings for the length of the period of operation can be made. Thecam IT has a central opening I00, which receives the shaft Hi. It alsohas the threeholes l0i, I02 and I03, through which may pass the screwI04. The cam I! also has an arcuate slot I05. In the periphery of thecam I! are the three depressions I06, I01 and I08 of various lengths.

In Fig. 15 is shown the second lamination lliA which contains an arcuateslot I which registers with the slot I but is somewhat shorter. Themember HA is also provided with a second arcuate slot IIO from one sideof which projects an ear I I I, which facilitates the movement of themember I1A. Four equidistant notches I I2 of uniform length are formedaround the perimeter of the member HA.

The third disc HE is provided with four arcuate notches I I3, which arealso of uniform length and size, as are the notches II2. The plate HE isprovided with an inturned ear I8, which extends forwardly through theslots I05 and I09. The plate IIB also has an indicator point 20 which00- copies space with the slot H0 and can register with the calibrationsII 5 on the disc HA. The

purpose of this construction is as follows:

The relative position of the members I1 and HA determine the number ofdepressions II2 which will be exposed, that is, if the screw I04 is inthe hOle I01. then only one depression is exposed. If the screw I04 isin the hole I02, then two depressions are exposed, meaning of course,that the stoker will be operated once every hour, while if the screw I04is in the hole I03, four depressions will be exposed, causing the stokerto operate very half hour. Now it will be noted that the screw I04passes through the arcuate slot I 09 so that the plates HA and H13 canbe adjusted with relation to each other. That is, they can be moved sothat the notches I I2 and H3 are not in exact register or they can varythe length of the stoker operation, the amount of which is indicated bythe pointer on the scale I I5.

It will be noted that the screw I04 while passing through the openingI09 extends into the hole I I1 in the cam member ITB so that the plateI1A can be clamped between the members I1 and H13. It follows then thatby means of the three discs I1, 11A and I'll there is provided a singlecam by means of which the motor may be operated a different number oftimes in a given period. and the length of the operation can be varied.

Motion is supplied to the shaft I6 through its gear 2I by the motor 22which operates the train of gears 23 of which the gear 2| is anintermediate.

A stoker motor 24 is indicated as being connected to the power leads 25and 26. The lead 26 includes the electrically operated switch 21 whichis operated by means of a solenoid 28, whose lead 28 is connected to oneside of the transformer secondary 30, whose terminal 3| has connectedthereto a lead 32 which is connected to the contact point 33 of thethermostat 34 whose terminal 35 is connected by the lead 36 to the post31 on which is mounted the arm 38 on which is disposed the contact point39 of the switch I8. The arm 40 is connected to the terminal 3| andcarries on its outer end the contact point 4| which is adapted toregister with the contact point 39 when the roller 42 of the arm 38falls into a depression 43 of the cam I1. 1

The primary 44 of the transformer 45 and the timing motor 22 whichdrives the cam disc I1, are each connected across the power leads 25 and26.

Referring particularly to my invention as illustrated in Figs. l-6inclusive, it will be noted that the gear 2I has pivotally mountedthereon a lever 41 of insulating material whose uppermost end 48isadapted to ride against one side of the cleanfire switch arm 49 whichis connected by a lead 50 to one side of the solenoid 28. The switchblade II is connected to the post 31 and it is across the points 52 ofthe members 49 and 5| that current flows to the solenoid 28 of thestoker motor switch 21.

Pivotally mounted on the lever 41 by means of a rivet 53 is the lever54, whose pawl 55 is adapted to engage the teeth of the gear 2I anddrive the lever 41 in a clockwise direction as shown in position shownin Fig. 6. The lever 54 also has a laterally turned lug 56 which isengaged by the projection 51 of the lever 41 and serves as a backwardstop for the pawl 55 and limits the relative angularity of the members48 and 54. The lever 54 also has an upturned lower portion 54--B whichfunctions as a counterweight for the engagement of the pawl 55.

The operation of this form of the device is as follows:

Assuming that the stoker motor 24 is being operated under the control ofthe thermostatic element 34 and that the contact points of the switch 52are closed by reason of the fact that the end 54--A of the switch lever54 is at zero position, that is, opposite to the one shown in Fig. 1;and that the operator desires to tend the stoker for the purpose ofremoving the ashes or performing some operation during which time hedoes not wish the stoker to be operated for any reason; instead ofopening the manual motor switch 58, which he might forget to re-closewhen his task is completed, he merely moves the end 54- -A of theclean-fire switch lever 54 to the position shown in Fig. 1 in which itregisters with the character 59, which in this case represents 15minutes of shut-down. This action causes the end 48 of the insulatedlever 41 to separate the contact points 52 and stop the flow of currentto the solenoid 28.

Since the gear 2| is driven by the motor 22. which is still operating,it follows that when the predetermined time has elapsed, the gear 2|through the pawl 55 will move the lever end 40 away from the arm 49permitting the contact points 52 to reengage. The gear 2I then moves thepawl 55 out of mesh as the lever end 54--A is restrained by the end ofthe slot. Obviously, the length of the stoker shut-down is determined bythe setting of the lever 54-1A.

In the form of the device shown in Figs. 7-11 inclusive, the operationis identical with that shown in Figs. 16, the difference being only inthe means employed to accomplish the results. In this form of the devicethe stationary bracket 60 is mounted on the plate I5-A and has securedthereto a piece of insulating material 6| to which is secured a movableswitch blade 52 which is connected by means of a lead wire 62-A to thepost 31. The switch blade 62 has an arcuate portion 63 formed thereonwhose center is along the axis of the pivot 64 of the gear 2I-A whichcorresponds with the gear 2| in the first descriptive form of the deviceand is driven in a like manner from the train of gears 23. Mounted onthe pivot 64 is a lever 65 on which is rotatably mounted the pinion 66which meshes with and is driven by the gear 2I--A. Secured to the pinion6B is a fiber disc 61 which is in alignment with the arcuate portion 63of the blade 52,

The end 68 of the lever 65 projects through the slot 48A in the plateI5A and when it is in zero or on position leaves the parts as shown inFig. '7; that is, with the disc 61 out of engagement with the blade 62and benig idly driven around by the gear 2I-A. If then, the lever end 68is moved to the fifteen minute position, the parts will take theposition shown in Fig. 9, in

which the disc 61 rides under the arcuate portion 63 of the blade 62 andseparates the contact point 89 from the contact point of the blade 1|which is mounted on the insulator 6| and is connected by means of thelead 'HA to one side of the solenoid 23.

It can be seen that any subsequent driving ac tion of the gear Zl-A willrotate the disc and drive it away from its switch opening position inprecisely the same manner as described in Figs. 1-6.

In the form of the device shown in Figs. 12 and 13, the same operationis performed by means of a thermal timer; that is, the clean-fire switchopened manually and closed automatically after a predetermined lapse oftime.

In this form of the device, the stoker motor 24-A has one lead 12connected to the contact 13 of the thermostat 14 whose lead 15 isconnected to the stationary switch blade 16 which is spaced from thestationary switch blade TI. The blade I1 is connected by means of thelead 18 to a re sistance element!!! which is connected by a lead 80 toone side 8| of the power line which is connected to the motor 24-A.Disposed between the blades 18 and TI is a rockable lever 82 which ismounted on a pivot 83 on a fixed support 84'. The lever 82 has a pair ofnotches 85 and 86 formed therein adapted to engage the end 81 of abimetallic element 88 which is responsive to heat generated by theresistance element 19 and is mounted on the fixed bracket 89. The lever82 is urged in one direction by the spring 98.

To the lever 82 is secured a strip of insulating material 9| to which isattached the elongated switch blade 92 whose contact 93 is adapted toone age the contact 94 of the blade 16 during the normal operation ofthe stoker or to have its con+ tact 95 engage the contact 96 of theblade TI during a clean-fire period. The blade 92 is connected by theflexible lead 91 to the side 98 of the power circuit.

The operation of this form of the device is quite similar to the twoforms previously described and is stated as follows:

Assuming that the stoker is being operated in response to the thermostat14, that is, to satisfy some specific heating requirement, and it isdesired to tend the stoker for some purpose during which time it is verydesirable that the stoker be not operated, all that is necessary is tomov the lever 82 to the position shown in Fig. 12, which will cause thebimetallic element 88 to engage the notch 86 due to the spring tensionin the member 88, causing an interruption in the flow of ourrent to thestoker motor 24-A, and at the same time causing current to flow to theheater or resistance element 19 until it eventually warms the element 88sufiiciently to cause it to bend to the form shown in Fig. 13, that is,releasing the lever 82 and restoring the equipment to a condition whichwill operate the motor 24%.

For the purpose of simplifyingthe illustration and description, I haveomitted the intermittent operating mechanism, although it can be seenthat the form of the device shown in Figs, 12 and 13 would functionsatisfactorily in conjunction with a time interval contactor.

While I have thus illustrated and described my invention, it is not myintention to be limited to the precise embodiment shown therein, butintend, rather, to cover such forms and modifications thereof as fallfairly within the appended claims.

I claim:

1. A fire tending switch disposed in the motor control circuit of astoker consisting of a pair of switch blades normally closed by springaction, one of said blades having an arcuate extension formed thereon, acontinuously rotating time driven gear associated with said switch, aplanetary pinion meshing with said gear and having a disc mountedthereon, said disc passing under said arcuate extension in a manner tomove same and thereby open said switch, and whereby said disc may bemanually moved to said switch opening position and driven by said gearto a switch closing position.

2. A spring closed fire tending switch interposed in a motor controlcircuit of a stoker consisting of a continuously rotating time drivengear, a planetary pinion meshing with said gear, a disc drivablyconnected to said pinion, a switch blade in the path of said disc andadapted to be opened thereby, whereby said pinion may be manually movedtoward said blade and whereby the driving action of said pinion willcause said disc to roll away from said blade and permit said switch toclose under the action of said gear.

3. A switch actuator consisting of a movable switch blade, acontinuously rotating gear associated therewith, a plantary pinionmeshing with ,said gear, a disc driven by said pinion and disposed inthe path of said blade, said disc being free to be swung manuallyagainst said blade and frictionally engage same in a manner to open saidswitch, and to be driven by said gear to roll away from said blade, andto close said switch after a predetermined lapse of time.

LAWRENCE R. TEEPLE.

